Justus diehl



(fin Model'.)

. J. DIEHL.

PIANO SOUNDING BOARD. No. 280,362 Patented July 3, 1883.

T WITNESSES INVENTOR:

ATTORNEYS.

Nv PETERS. Phublflhognpher, Washington. D. C.

UNITED STATES PATENT OFFICE.

JUSTUS DIEHL, OF NEW YORK, N. Y.

PIANO SOUNDING-IBOARD.

SPECIFICATION forming part of Letters Patent No. 280,362, dated July 3, 1883.

I Application filed August 11, 1EB2. (No model) frame, and provided with a single opening for the escape of the sound.

My invention consists in forming such a sound-chest with the opening made in the main sound-board, extending across the same from side to side, or formed wholly in said board, and in combining with the soundboards a number of sound-posts, which are secured to the inner surfaces of the soundboards in such manner that the boards may be drawn inward tightly against the ends of the posts, whereby the boards shall always vibrate in perfect unison with each other.

In the drawings, Figure 1 is a front elevation of my invention as adapted to upright pianos. Fig; 2 is a vertical section on line a, Fig. 1; and Fig. 3 is a horizontal section of the same on line y y, Fig. 1, showing the opening in the board formed near its center instead of at one edge.

Heretofore a sound-chest for a piano has been formed with two sound-boards, the upper one of which, together with the end of the chest, is cut away at one corner to form an opening for the escape of the sound. An open sound-chest has also been formed with two sound-boards, one of which is supported above the strings by means of standards or posts, to which it is secured by screws. Now, the object of my invention is to provide a sound chest having the opening extended across the main sound-board from side to side or formed wholly in said sound-board, with which shall be combined a number of sound posts adapted to draw the sound-boards or the sound-board proper and the back or bottom of the chest inward toward each other, and to hold them tightly in contact therewith, to the end that the two boards shall be adapted to vi brate in perfect unison with each other.

A indicates the sounding-board, which may be constructed with an opening, 13, near its center, or with an opening, 0, formed by cut- 55 ting away its upper edge on a curved line,

The box D, to which the sounding-board is secured, is completely closed at the sides and back, so that there shall be no opening leading therein, except the opening in the said board. The inner surfaces of the soundingboard and the back of the box are provided with ribs, as shown.

Between the sounding-board and the back of the box are provided one or more posts, E, which are provided at their ends with a screw threaded bolt, 0, and secured in position by means of nuts 6, screwing on theends of the bolt, which project through perforations in the board and back. By screwing up the nuts the back and the sounding-board will be firmly connected together, so as to vibrate in unison when the chords are struck. The sounding post or posts, instead of being placed in contact with the inner surfaces of the board and T back, may be secured between corresponding ribs on the board and back, and they may also be secured in position by means of screws driven into their ends from outside the box.

In a grand piano, owing to the horizontal position of the sounding-board, the posts may be secured in place without the use of the ex pedients above described. When used in a grand piano, the board is to be provided with an opening near the center, as shown in Fig. 3, instead of at. one edge, in order that the hammer mechanism may be arranged entirely outside the box.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

The combination of the back board and sound-board, constructed and arranged as described, the intervening supporting-frame, to which the back and sound-board are secured to form a close chamber, and the sound-posts arranged between the boards, and having bolts passing through them and provided with nuts for securing them to the boards, whereby the latter may be drawn inward and held under tension against the intervening frame, and whereby the said tension may be regulated according to natural changes in temperature, substantially as specified.

USTUS DIEHL.

Witnesses:

O. Snnewrox, ALFRED LUROOTT. 

